Entamoeba histolytica: In Silico and In Vitro Oligomerization of EhHSTF5 Enhances Its Binding to the HSE of the EhPgp5 Gene Promoter.

Throughout its lifecycle, Entamoeba histolytica encounters a variety of stressful conditions. This parasite possesses Heat Shock Response Elements (HSEs) which are crucial for regulating the expression of various genes, aiding in its adaptation and survival. These HSEs are regulated by Heat Shock Transcription Factors (EhHSTFs). Our research has identified seven such factors in the parasite, designated as EhHSTF1 through to EhHSTF7. Significantly, under heat shock conditions and in the presence of the antiamoebic compound emetine, EhHSTF5, EhHSTF6, and EhHSTF7 show overexpression, highlighting their essential role in gene response to these stressors. Currently, only EhHSTF7 has been confirmed to recognize the HSE as a promoter of the EhPgp5 gene (HSE_EhPgp5), leaving the binding potential of the other EhHSTFs to HSEs yet to be explored. Consequently, our study aimed to examine, both in vitro and in silico, the oligomerization, and binding capabilities of the recombinant EhHSTF5 protein (rEhHSTF5) to HSE_EhPgp5. The in vitro results indicate that the oligomerization of rEhHSTF5 is concentration-dependent, with its dimeric conformation showing a higher affinity for HSE_EhPgp5 than its monomeric state. In silico analysis suggests that the alpha 3 α-helix (α3-helix) of the DNA-binding domain (DBD5) of EhHSTF5 is crucial in binding to the major groove of HSE, primarily through hydrogen bonding and salt-bridge interactions. In summary, our results highlight the importance of oligomerization in enhancing the affinity of rEhHSTF5 for HSE_EhPgp5 and demonstrate its ability to specifically recognize structural motifs within HSE_EhPgp5. These insights significantly contribute to our understanding of one of the potential molecular mechanisms employed by this parasite to efficiently respond to various stressors, thereby enabling successful adaptation and survival within its host environment.

[Determination and analysis of protein profile of different transfer factors]. / Determinación y análisis del perfil proteico de diferentes factores de transferencia.

BACKGROUND: The transfer factor (TF) is the dialyzable extract of leukocytes with cellular immunity transfer properties. Its use has spread in the treatment of a wide range of immunologic, infectious, and even oncological diseases. However, important aspects in their protein profile, component concentrations, and a well-defined action mechanism are not completely unknown. OBJECTIVES: To analyze the protein profiles of different transfer factors marketed in Mexico. METHODS: 6 TF marketed in Mexico were obtained and analyzed, quantifying protein with thaze Bradford method, by high-performance liquid chromatography (HPLC), and polyacrylamide gel electrophoresis (SDS-PAGE). All samples were analyzed in duplicate. RESULTS: The total protein concentrations of all TF analyzed are less than 0.2 mg/mL. The chromatographic profiles showed differences in some TF. The protein concentration was 6 to almost one thousand times lower compared to reports by some manufacturers. CONCLUSION: Almost all transfer factors marketed in Mexico lack a labeling and health record that meets the official standards.

Introducción: El factor de transferencia (FT) es el extracto dializable de leucocitos con propiedades de transferencia de inmunidad celular. Su uso se ha extendido en el tratamiento de una amplia gama de padecimientos inmunológicos, infecciosos y como coadyuvante de padecimientos oncológicos. A pesar de ello, no se conocen completamente aspectos importantes de su perfil proteico, concentraciones de componentes y mecanismos de acción. Objetivos: Analizar los perfiles proteicos de diferentes factores de transferencia comercializados en México. Métodos: Se obtuvieron y analizaron 6 FT comercializados en México. Se realizó la cuantificación de proteínas por el método de Bradford, cromatografía líquida de alta resolución (HPLC) y electroforesis en geles de poliacrilamida (SDS-PAGE). Todas las muestras fueron analizadas por duplicado. Resultados: Las concentraciones de proteínas totales de todos los FT analizados fueron menores de 0.2 mg/mL. Los perfiles cromatográficos mostraron diferencias en algunos FT. La concentración de proteínas resultó de 6 hasta casi mil veces más baja en comparación con lo informado por algunos fabricantes. Conclusión: Casi la totalidad de los factores de transferencia comercializados en México carecen de un etiquetado y registro sanitario que cumpla con las normas oficiales vigentes.

[Profilins: allergens with clinical relevance]. / Profilinas: alergenos con relevancia clínica.

INTRODUCTION: Profilins are small ubiquitous proteins of 12-19 kDa involved in actin dynamics. These proteins are found in all eukaryotic organisms studied to date. Profilins have aminoacid sequences and tridimensional structure highly conserved. Allergy patients to pollen frequently have symptoms of allergy when ingestion of plant-derived foods like fruits, vegetables, seeds, among others. This phenomenon is known as latex-pollen-fruit allergy and it's the main cause of oral allergy syndrome (OAS) which is attributed to the cross-reactivity. Allergens shared between different sources theses are called panallergens for example are profilins which representing at least 20% of all pollen allergic patients. This cross-reactivity is results from the high amino acid sequence identity of profilin from plants, which is between 70% and 85%, this may explain the exacerbation symptoms of allergic patients to profilins from plants. OBJECTIVE: We described some characteristics which show us the important participation of the profilins in the sensitization of people allergic, especially to plants, fruits and pollen. METHODS: We looked research aminoacid sequences of all allergenic profilins reported to date and these were analyzed. CONCLUSIONS: Profilins are important allergens that are underrated in clinical practice and contribute to cross-reactivity in sensitized individuals by profilins from other sources.